Background: This study aimed to validate the role of the D-dimer to lymphocyte ratio (DLR) for mortality prediction in a large national cohort of hospitalized coronavirus disease 2019 (COVID-19) patients. Methods: A retrospective, multicenter, observational study that included hospitalized patients due to SARS-CoV-2 infection in Spain was conducted from March 2020 to March 2022. All biomarkers and laboratory indices analyzed were measured once at admission. Results: A total of 10,575 COVID-19 patients were included in this study. The mean age of participants was 66.9 (±16) years, and 58.6% (6202 patients) of them were male. The overall mortality rate was 16.3% (n = 1726 patients). Intensive care unit admission was needed in 10.5% (n = 1106 patients), non-invasive mechanical ventilation was required in 8.8% (n = 923 patients), and orotracheal intubation was required in 7.5% (789 patients). DLR presented a c-statistic of 0.69 (95% CI, 0.68–0.71) for in-hospital mortality with an optimal cut-off above 1. Multivariate analysis showed an independent association for in-hospital mortality for DLR > 1 (adjusted OR 2.09, 95% CI 1.09–4.04; p = 0.03); in the same way, survival analysis showed a higher mortality risk for DLR > 1 (HR 2.24; 95% CI 2.03–2.47; p < 0.01). Further, no other laboratory indices showed an independent association for mortality in multivariate analysis. Conclusions: This study confirmed the usefulness of DLR as a prognostic biomarker for mortality associated with SARS-CoV-2 infection, being an accessible, cost-effective, and easy-to-use biomarker in daily clinical practice.

The primary aim of this study was to describe the prevalence and characteristics of lung ultrasound abnormalities six months after hospital discharge for COVID-19 pneumonia. This prospective observational study included patients hospitalised with COVID-19 pneumonia between March 2020 and May 2022. Participants attended a follow-up visit between one and six months after discharge. A standardised 14-zone ultrasound protocol was applied in all cases. Clinical variables and symptoms, including dyspnoea graded using the modified Medical Research Council (mMRC) scale, were recorded. The median time from discharge to follow-up assessment was 75 days. Lung involvement on ultrasound was frequent, observed in 79.3%. The most common findings were pleural line irregularities with B-lines (75.9%) and subpleural consolidations (35.6%). A B-line count ≥ 3 per segment was noted in 38.3%. Abnormalities were more common in the basal lung regions. Dyspnoea was the main respiratory symptom, reported by 67% with varying degrees on the mMRC scale. COVID-19 pneumonia remains a significant public health concern, particularly among high-risk groups susceptible to severe disease and post-COVID sequelae. Efficient screening methods are needed for evaluating potential sequelae. The technical features of lung ultrasound—its accessibility, safety, reproducibility, and ability to detect pulmonary abnormalities during post-COVID follow-up—may render it a valuable tool for patient monitoring. In our series, lung ultrasound findings (pleural line irregularities, B-lines, and subpleural consolidations) were frequent. However, further studies correlating sonographic findings with associated factors and persistent symptoms are required to confirm and validate its role in this setting.

Background/Objectives: The clinical determinants and functional relevance of persistent lung ultrasound (LUS) abnormalities after COVID-19 pneumonia remain poorly characterized. We aimed to identify determinants of qualitative LUS abnormalities and global lung involvement assessed by the LUS score, and to evaluate their association with persistent dyspnoea. Methods: We conducted a prospective observational study that included 261 patients who were hospitalized for COVID-19 pneumonia and were assessed 1–6 months after discharge. A standardized 14-zone LUS protocol was used to assess qualitative abnormalities (pleural line irregularity, ≥3 B-lines, and subpleural consolidations) and to calculate the LUS score. Associations with clinical variables, including dyspnoea assessed by the modified Medical Research Council (mMRC) scale, were analyzed using multivariable logistic regression. Results: The severity of the acute pneumonia episode emerged as the strongest determinant of qualitative LUS abnormalities and elevated LUS score (>6). Increasing age was independently associated with ultrasound findings. Persistent dyspnoea (mMRC ≥ 1) was associated with all qualitative abnormalities and with a higher prevalence of elevated LUS score (56.6% vs. 22.1%; p < 0.001). A graded association was observed between dyspnoea severity and both qualitative findings and LUS score. An increase in dyspnoea from baseline (ΔmMRC ≥ 1) remained independently associated with an elevated LUS score. Conclusions: Persistent LUS abnormalities are strongly associated with the severity of the acute episode. The LUS score provides a robust, clinically meaningful measure of residual lung involvement and shows a stronger association with persistent dyspnoea than qualitative findings, supporting its role in follow-up and risk stratification.